[lkml]   [2006]   [Oct]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: USB performance bug since kernel 2.6.13 (CRITICAL???)
On Thu, 2006-10-12 at 12:33 -0700, Open Source wrote:
> I am using a device that submits URBs asynchronously using the libusb
> devio infrastructure. In version 2.6.12 I am able to submit and reap
> URBs for my particular application at a transaction rate of one per
> millisecond. A transaction consists of a single WRITE URB (< 512
> bytes) followed by a single READ URB (1024 bytes). Once I upgrade to
> version 2.6.13, the transactional rate drops to one per 4
> milliseconds!

The kernel's internal tick rate was lowered from 1000Hz to 250Hz
starting with 2.6.13. Rebuild with CONFIG_HZ=1000 and the performance
should return to normal.


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2006-10-12 21:57    [W:0.039 / U:0.144 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site